1. Field of the Invention
The present invention relates to a corona discharger suitable for use in charging or charge-removing of a surface to which the corona discharge is applied.
2. Description of the Prior Art
Known corona dischargers used in electrophotographic systems, electrostatic recording systems and so on include a corotron device comprising a corona discharging wire connected with a source of high voltage and a shielding plate surrounding the corona discharging wire and a scorotron device comprising the corotron device and a corona discharge current controlling member provided within the above corotron device, which member will be called a "grid". Each of these devices functions to create a corona discharge when a high voltage is applied to the corona discharge wire. This cannot avoid the dust collecting action due to the corona discharge such that the corona discharging wire, grid, shielding plate and other elements will be contaminated by foreign matters such as scattered developer particles, oxides produced under the corona discharge, dust in the air, powdered paper material and others. Particularly, the contaminated corona discharge wire and the grid tend to cause an irregular discharge so that a surface to which the corona discharge is applied will not uniformly be charge or charge-removed. Thus, an operator must periodically clean the corona discharge wire and the grid by using a cleaning member to maintain the desired function of corona discharge.